Multi-Tier Supply Chain Defect Liability Allocation in Commission Dyeing Operations
Commission dyeing defect liability requires contractual tripartite agreements, pre-process greige verification gates, and analytical fault isolation.
Cuprammonium Fluidity
Chemical Degradation
Viscometric measurement of dissolved cellulose determines the extent of macromolecular damage in cotton and linen fabrics. In textile laboratory testing, cuprammonium fluidity measures the rate of flow of a solution containing dissolved cotton fibres through a calibrated glass capillary tube. This test indicates the degree of polymerization of the cellulose chain, which decreases when the fibre is exposed to aggressive chemical bleaching or excessive thermal drying.
The value is expressed in rhes, representing the reciprocal of viscosity in poises.
Bleaching Control
Bleaching control relies on this metric to assess the safety of hydrogen peroxide or sodium hypochlorite applications. While scouring removes natural waxes, cuprammonium fluidity reveals if the bleaching cycle has degraded the cellulose structure itself. A high fluidity value indicates that the cotton has been over-bleached, which correlates directly with a loss in fabric tensile strength.
Viscosity Measurement
Viscosity measurement requires the complete exclusion of oxygen to prevent autoxidation of the cellulose during the dissolution phase. The laboratory technician dissolves a precise mass of dry, shredded cotton in the cuprammonium hydroxide solvent under a nitrogen atmosphere. Once the polymer is fully dispersed, the solution is drawn into the viscometer, and the time required for a fixed volume to flow between two etched lines is measured.
This elapsed time is converted to a fluidity value using a calibration constant specific to the glass tube.
Specification Limit
Specification limit values vary depending on the intended use of the finished cotton goods. For apparel fabrics, a cuprammonium fluidity value below five rhes indicates negligible chemical damage, whereas values exceeding ten rhes suggest significant degradation that will lead to premature failure in laundering. Industrial laundries use this test to monitor the degradation of bed linens and workwear over repeated washing cycles.